I used to know a guy who hated Mercedes cars because they didn't have names. Instead, Mercedes simply gives its vehicles identifiers like E300, SL550, or AMG GLE43. I imagine that guy probably wouldn't like Cooler Master's newest mouse, either. It's simply called the MM531.
OK, technically it's the MasterMouse MM531. You might think that MM stands for MasterMouse, but you'd apparently be as wrong as I was. Fortunately, Cooler Master refers to the mouse primarily as the MM531, so that's what we're going to use too.
You've probably already divined this from the picture above, but this is a by-the-numbers seven-button gaming mouse. It features RGB LED lighting, an ergonomic right-handed shape, and not much else. Like the Cooler Master CK552 keyboard that I just reviewed, there really aren't any gimmicks here. We don't get any adjustable weights or interchangeable side panels, or really anything beyond the essentials.
The shape of the MM531 isn't unusual, which means my claw-gripping hands feel right at home. Likewise, palm-grip players will find much to love about the MM531's wide back end. Fingertip grippers will need to have quite long fingers indeed, though. The geometrically-indented rubber pads on the sides aren't as soft or sticky as those on the Steelseries Rival 310, but they also seem like they'll be more durable.
Meanwhile, the MM531's deep-set mouse wheel does a lot less to impede the shine of its vibrant RGB LED lighting than it did on Steelseries' mouse. The whole wheel is formed from a translucent rubbery substance. However, the mouse wheel's click has an extremely short throw to it, which isn't the greatest feeling in the world. Best reassign mouse button 3 elsewhere.
The primary buttons are formed from PBT plastic to keep them from turning shiny. They're nice and responsive with clear feedback and exactly the right amount of throw. Over on the side, the thumb buttons are easy to reach and perform well, too. PixArt's PMW3360 optical sensor is as good as it usually is, which is to say that it's pretty great. Set to the same 1600 DPI, the MM531 actually feels remarkably like the Rival 310.
I do have one design quibble with this mouse: the two top buttons behind the mouse wheel are puny and too proximate to one another. I don't like buttons that sit behind the wheel on any mouse—I find them awkward to press—but on this mouse they are especially lamentable thanks to their size and spacing.